1. Field of the Invention
The present invention relates to a torsional vibration damper with a drive-side primary element having at least one primary dog, with an output-side secondary element having at least one secondary dog and with at least one spring device between the primary dog and secondary dog for the spring-elastic coupling of the primary element and secondary element.
2. Description of the Related Art
A multiplicity of torsional vibration dampers or rotary vibration dampers are known in various fields of use from the prior art. The known torsional vibration dampers are used, in particular, in motor vehicle construction for the elastic coupling of the internal combustion engine and drive train. This is intended to prevent torsional vibrations from being transferred from the internal combustion engine to the drive train or to the transmission. Such a transfer of torsional vibrations occurs particularly in internal combustion engines having comparatively few cylinders and at low rotational speeds. With an effective damping of such vibrations, the internal combustion engine can be operated at lower rotational speeds, thus generally resulting in a reduced fuel consumption.
Thus, EP 1584838 A1 describes a torsional vibration damper with a drive-side primary element and with an output-side secondary element, the primary element being coupled spring-elastically to the secondary element via a spring device, so that these elements can be rotated with respect to one another about a “neutral” position. The primary and secondary elements comprise in each case dogs which are adjacent to the spring device and which are designated below as a primary and a secondary dog. A torque prevailing at the primary element on the drive side can thus be transferred by means of the primary dog first to the spring device and from the spring device to the secondary element via the secondary dog. The drive-side primary element is designed as a one-piece middle disk having primary dogs projecting radially outward.
DE 199 58 814 A1 describes a similar rotary vibration damper in the form of a two-mass flywheel. The known rotary vibration damper has a central disk element with a plurality of supporting arms arranged on the circumference, and a further disk element composed of two cover disk elements on which supporting projections are provided. Between the supporting arms and the supporting projections, spring devices are provided for the spring-elastic coupling of the central disk element and the further disk element. Here, too, the central disk element is produced in one piece.
The torsional or rotary vibration dampers known from the prior art have the disadvantage that high transfer noises may occur particularly during a traction/overrun change. This is attributable to the fact that, in a traction/overrun change, the primary dogs or supporting arms may lift off briefly from the spring device in order subsequently to impinge again on an end spring or an end saddle of the spring device. This may even be such that the vibration of the primary element or central disk element is transferred via its drive shaft to the engine, thus resulting in the generation of a particularly high noise.
An object of the present invention, therefore, is to provide a torsional vibration damper which can be operated with particularly low noise.